No explanation from the devs. We've only had Cam tell us they may look into the issue after release. I can't recall how far back in the thread, there was some speculation that it may have something to do with clipping? Tying the hair to specific horns means less issues?
I don't think it's a very compelling argument, but it's a possibility.
It's absolutely not a compelling argument at all. That's why a LOT of is here asked (politely) for an explanation from a dev who actually worked on the hair or knows what they're talking about.
We still haven't received any sort of explanation as to why the devs chose to give the bald Qunari necrotic craters, why a hornless Qunari can't share hairstyles with the other races, why the textures of Qunari hair look like crap, and WHY they couldn't separate horn sliders. I appreciate that someone from Bioware took the time to respond (In VERY general terms) that they were aware of our concerns, but they didn't even bother to tell us WHY they made all of these baffling choices.
Granted, they don't owe us anything and can do whatever they want, but some sort of explanation would do a LOT to smooth things over.
I could live without the metal-plated horn styles (and a couple of the broken ones) if it meant more hair styles... but I know some people are very excited by the metal-plated/broken horns, so. 
As far as I'm aware, metal plated horns are not even part of the established lore. It's cool they added the option, but if they did it at the expense of giving us more hairstyles I would be PISSED considering all of their prior concept art of qunari's depict them with long hair.
Just as a heads up, Mike rarely responds to me when I tweet him. I wouldn't read much into a lack of response.
In fact I can only recall one time when Mike responded to me directly, and it was a retweet of something I said to him so it could be argued he didn't actually respond to me.
I'm sure he's incredibly busy, but what kind of guarantee do we have that Mike (or the people on the dev team that work on stuff like hair) *actually* are aware of our concerns if they themselves don't address it or explain their rationale to us? Maybe I'm being cynical but after seeing how the qunari's got the short end of the stick when it comes to the hair, it makes me wonder...